Mitsubishi Electric PUHZ-SW HA Series Installation Manual page 8

4. Installing the refrigerant piping
4.6. Addition of refrigerant
• Additional charging is not necessary if the pipe length does not exceed 10 m
(SW40-120), 30 m (SW160, 200).
• If the pipe length exceeds 10 m (SW40-120), 30 m (SW160, 200), charge the
unit with additional R410A refrigerant according to the permitted pipe lengths in
the chart below.
* When the unit is stopped, charge the unit with the additional refrigerant
through the liquid stop valve after the pipe extensions and indoor unit have
been vacuumized.
When the unit is operating, add refrigerant to the gas check valve using a
safety charger. Do not add liquid refrigerant directly to the check valve.
Permitted Permitted
Model pipe vertical
length difference
SW40, 50 2 m - 40 m -10 m
SW75 2 m - 40 m -10 m
SW100, 120 2 m - 75 m -30 m
Permitted Permitted
Model pipe vertical
length difference
SW160 2 m - 80 m -30 m
SW200 2 m - 80 m -30 m
When length exceeds 70 m
When the total length of the piping exceeds 70 m, calculate the amount of additional charge based on the following requirements.
Note: If the calculation produces a negative number (i.e. a “minus” charge), or if calculation results in an amount that is less than the “Additional charge amount for 70 m”,
perform the additional charge using the amount shown in “Additional charge amount for 70 m”.
Main piping:
Liquid line size
Amount of additional
ø12.7 overall length ×
charge
=
0.11
(m) × 0.11 (kg/m)
(kg)
SW160 3.6 kg
Additional charge amount
for 70 meters
SW200 4.8 kg
Additional refrigerant charging amount
11 - 20 m 21 - 30 m 31 - 40 m 41 - 50 m 51 - 60 m 61 - 75 m
0.2 kg 0.4 kg 0.6 kg —
0.4 kg 0.8 kg 1.4 kg —
0.2 kg 0.4 kg 1.0 kg 1.6 kg
Additional refrigerant charging amount
31 - 40 m 41 - 50 m 51 - 60 m 61 - 70 m
0.9 kg 1.8 kg 2.7 kg 3.6 kg
1.2 kg 2.4 kg 3.6 kg 4.8 kg
Main piping:
Liquid line size
ø9.52 overall length ×
+
0.09 (Gas line: ø25.4)
(m) × 0.09 (kg/m)
* After charging the unit with refrigerant, note the added refrigerant amount on
the service label (attached to the unit).
Refer to the “1.5. Using R410A refrigerant outdoor unit” for more information.
• Be careful when installing multiple units. Connecting to an incorrect indoor unit
can lead to abnormally high pressure and have a serious effect on operation
performance.
— —
— —
2.2 kg 2.8 kg
71 - 80 m
Calculate the amount
of additional refrigerant
charge using formula
Branch piping: Branch piping:
Liquid line size Liquid line size
ø9.52 overall length × ø6.35 overall length ×
+ +
0.06 (Gas line: ø15.88) 0.02
(m) × 0.06 (kg/m)
(m) × 0.02 (kg/m)
–
3.6 (kg)